Lacquer hardenable by UV radiation

Abstract

UV hardenable lacquer, in particular for molded polycarbonate (PC) bodies, comprising: (A) 5 to 60%, referring to the total weight of 100% of the entire mixture, of an aliphatic polyurethane acrylate, preferably 5 to 20% of a hexa-functional PU acrylate; (B) 30 to 45%, referring to the total weight of 100% of the entire mixture, of a cross-linkable, polyfunctional acrylate having less than 20 C atoms in the molecule; (C) 0.01 to 3%, referring to the total weight of 100% of the entire mixture, of a cross-linkable polyfunctional silicon acrylate; (D) if required, between 1 and 5%, referring to the total weight of 100% of the entire mixture, of a monofunctional, ethylenically unsaturated compound such as N-vinyl pyrrolidone; (E) 0 to 70% referring to the total weight of 100% of the entire mixture, of organic solvents; (F) photo initiators; and (G) light protector.

What is claimed is: 
     
       1. A UV hardenable lacquer suitable for coating molded polycarbonate (PC) bodies, comprising: (A) 5 to 60%, based on a total weight of 100% of the entire mixture, of a cross-linkable aliphatic polyurethane acrylate;   (B) 30 to 45%, based on the total weight of 100% of the entire mixture, of a cross-linkable, polyfunctional acrylate having less than 20 C atoms in the molecule;   (C) 0.01 to 3%, based on the total weight of 100% of the entire mixture, of a cross-linkable polyfunctional silicon acrylate;   (D) optionally, between 1 and 5%, based on the total weight of 100% of the entire mixture, of a monofunctional, ethylenically unsaturated compound;   (E) an amount up to 70% based on the total weight of 100% of the entire mixture, of at least one organic solvent, wherein said organic solvent is a mixture of 0 to 20% of an ester and 80 to 100% of a mixture of alcohols with varying evaporation rates;   (F) a photo initiator;   (G) optionally, a light protector.   
     
     
       2. A UV hardenable lacquer in accordance with claim 1, wherein the aliphatic polyurethane acrylate has a molecular weight of 800 to 1200. 
     
     
       3. A UV hardenable lacquer in accordance with claim 1, wherein the polyfunctional acrylate comprises a pentaerythritol tri- or tetraacrylate. 
     
     
       4. A UV hardenable lacquer in accordance with claim 1, wherein the polyfunctional acrylate is tri-functional, tetra-functional, or a mixture of tri- and tetra-functional acrylates. 
     
     
       5. A UV hardenable lacquer in accordance with claim 1, wherein the polyfunctional silicon acrylate is di- up to hexa-functional. 
     
     
       6. A UV hardenable lacquer in accordance with claim 1, wherein said light protector comprises an amine with steric hindrance. 
     
     
       7. A UV hardenable lacquer in accordance with claim 1, comprising 5-20% of a hexa-functional polyurethane acrylate. 
     
     
       8. A UV hardenable lacquer in accordance with claim 1, wherein said ethylenically unsaturated compound is N-vinyl pyrrolidone. 
     
     
       9. A UV hardenable lacquer suitable for coating molded polycarbonate (PC) bodies, comprising: (A) 5 to 60%, based on a total weight of 100% of the entire mixture, of a cross-linkable aliphatic polyurethane acrylate;   (B) 30 to 45%, based on the total weight of 100% of the entire mixture, of a cross-linkable, polyfunctional acrylate having less than 20 C atoms in the molecule;   (C) 0.01 to 3%, based on the total weight of 100% of the entire mixture, of a cross-linkable polyfunctional silicon acrylate;   (D) optionally, between 1 and 5%, based on the total weight of 100% of the entire mixture, of a monofunctional, ethylenically unsaturated compound;   (E) an amount up to 70% based on the total weight of 100% of the entire mixture, of at least one organic solvent, wherein said organic solvent comprises a non-aprotic solvent;   (F) a photo initiator;   (G) optionally, a light protector.   
     
     
       10. A UV hardenable lacquer according to claim 9, wherein said solvent is present in an amount of approximately 48%. 
     
     
       11. A UV hardenable lacquer according to claim 9, wherein said photo-initiator is present in an amount of about 1%, said light protector is optionally present in an amount of up to 5% by weight, said ethylenically unsaturated compound is optionally present in said amount of between 1 and 5%, said cross-linkable polyfunctional silicon acrylate is present in said amount of 0.01 to 3%, said cross-linkable polyfunctional acrylate having less than 20 C atoms in the molecule is present in said amount of 30 to 45%, said aliphatic polyurethane acrylate is present in an amount of 5 to 20 parts by weight, the remainder consisting essentially of said at least one organic solvent.